JP3289513B2 - Speaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loudspeaker used for various kinds of audio equipment, and more particularly to a loudspeaker used in a field requiring heat resistance and flame retardancy.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a loudspeaker having a structure capable of sufficiently withstanding a large input even when a large input is applied. Heat resistance is becoming important. That is, when an input is applied to the voice coil, Joule heat is generated in the coil, and as the input increases, the generation of the Joule heat also increases. There has been such a problem that the wound bobbin is burned out, or the varnish connecting the coil and the bobbin is softened and deteriorated, and the coil comes off the bobbin.

In view of the above, a conventional voice coil is formed by cutting a metal foil into a strip shape into a cylindrical shape, and wrapping a reinforced paper made of kraft paper around the outer periphery to form a bobbin for reinforcement and insulation. However, by forming a voice coil by winding a coil around the bobbin, the heat of the coil portion is radiated by the metal foil to suppress the temperature rise. FIGS. 4 and 5 show a voice coil used for a speaker.

FIG. 4 is a half sectional view showing the structure of the conventional speaker. In FIG. 4, reference numeral 1 denotes a magnetic circuit. The magnetic circuit 1 is constituted by stacking and connecting a lower plate 3 having a center pole portion 2, a ring-shaped magnet 4, and a ring-shaped upper plate 5. . A frame 6 is connected to the upper surface of the magnetic circuit 1.
The outer peripheral portions of the gasket 7 and the diaphragm 8 are adhered to the peripheral portion of the substrate with an adhesive. A voice coil 9 is coupled to a center portion of the diaphragm 8, and an intermediate portion of the voice coil 9 is supported by a damper 10.
Is a magnetic gap 11 formed in the magnetic circuit 1.
And a dust cap 12 is attached to the upper surface of the central portion of the diaphragm 8.

FIG. 5 is a half sectional view showing a voice coil 9 used in a conventional speaker. As shown in FIG. 5, the conventional voice coil 9 is formed by forming a bobbin 19 made of a metal foil such as aluminum into a rectangular shape. And reinforced paper 1 made of kraft paper for reinforcement and insulation
5 is wound into a bobbin, and the coil 14 is wound around the bobbin to form the voice coil 9, and the heat generated in the coil portion is radiated by the metal foil to suppress the temperature rise. .

[0006]

However, in the above-mentioned conventional structure, the metal foil used as the bobbin 19 of the voice coil 9 is heavy in order to improve the heat resistance, so that not only the efficiency as a speaker is lowered but also the metal foil is reduced. Was not satisfactory because it had shortcomings such as short circuit due to good electrical conductors.

Further, a sheet made of heat-resistant chemical fiber, for example, aromatic polyamide paper, aramid paper (DUPONT)
There is also a case where the voice coil 9 is used as the bobbin 19 of the voice coil 9, but these have a small amount of hygroscopicity, and when the temperature of the voice coil 9 rises rapidly from 100 ° C. to 100 ° C. or more, the moisture becomes steam. By gasification, swelling occurs on the back side of the coil winding portion, or the bobbin material is difficult to cut, so that the aromatic polyamide fibers are likely to remain partially intact on the cut surface, or these fibers are feathered. However, they have a disadvantage that they cause abnormal quality of the speaker as abnormal sounds.

In recent years, there has been a demand for waterproofness of a door speaker for a vehicle, and water resistance is required for a voice coil including a diaphragm. However, there was a problem that there was no satisfactory product.

The present invention solves the above-mentioned conventional problems. By using a voice coil that is lightweight, has heat resistance, and is excellent in flame retardancy, waterproofness, and adhesiveness, it can sufficiently withstand a large input. It is an object to provide a possible speaker.

[0010]

Means for Solving the Problems In order to solve the above-mentioned problems, a speaker according to the present invention comprises, as a main component, an aromatic polyamide fiber having excellent heat resistance and exhibiting self-fusing properties by heating under pressure and calendering. And an inorganic filler having excellent rigidity and good heat resistance is 10 to 50 wt.
% As 100, and 5 to 40 w
A voice coil in which a coil is wound around a bobbin formed of a sheet obtained by coating or impregnating a metal alcoholate at a ratio of t% and heating, and a magnetic circuit having a magnetic gap in which the voice coil fits And a frame coupled to the upper surface of the magnetic circuit, and a vibration having an outer peripheral portion coupled to a peripheral edge of the frame and the voice coil coupled to a central portion.

[0011]

With this configuration, the bobbin of the voice coil has excellent dimensional stability to heat and excellent heat resistance. Since these have slight irregularities on the surface, they have excellent adhesiveness, good waterproofness, and good voice coil performance. It is possible to obtain a lightweight voice coil having excellent heat resistance without generating gas and bubbles due to heat generation.

The metal alcoholate has the effect of improving heat resistance and flame retardancy, and at the same time, improving rigidity, and improving wet heat resistance and water resistance. In addition, the sheet that becomes the bobbin is easier to cut, by preventing the burrs of the sheet cut surface and the fine fibers of the aromatic polyamide fibers from remaining without being cut, and by holding down the fibers that have appeared on the sheet surface,
A voice coil capable of improving abnormal sound can be obtained, and thus a speaker using the voice coil has high reliability that can sufficiently withstand a large input.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. Note that the same parts as those of the speaker of FIG. 4 described in the above conventional example will be described with the same reference numerals.

FIG. 1 is a half sectional view showing the structure of a speaker according to the embodiment. In FIG. 1, reference numeral 1 denotes a magnetic circuit.
The magnetic circuit 1 is constituted by laminating and connecting a lower plate 3 having a center pole portion 2, a ring-shaped magnet 4, and a ring-shaped upper plate 5. A frame 6 is coupled to the upper surface of the magnetic circuit 1, and the outer peripheral portions of the gasket 7 and the diaphragm 8 are attached to the peripheral edge of the frame 6 with an adhesive. A voice coil 13 is coupled to a center portion of the diaphragm 8, an intermediate portion of the voice coil 13 is supported by a damper 10, and a lower portion of the voice coil 13 is eccentric to a magnetic gap 11 formed in the magnetic circuit 1. The dust cap 12 is attached to the upper surface of the central portion of the diaphragm 8 without any problem.

FIG. 2 is a half sectional view showing a voice coil 13 used in the speaker according to the present embodiment.
In the figure, the voice coil 13 is composed of the bobbin 16 and the coil 1.
4. The voice coil 13 is constituted by a reinforcing paper 15. The voice coil 13 will be described in detail below.

That is, the voice coil 13 used in the loudspeaker according to the present invention is mainly composed of an aromatic polyamide fiber which is excellent in heat resistance and exerts self-fusing property by heating under pressure. A sheet obtained by mixing an inorganic filler, preferably 35 to 50% by weight of an inorganic filler, with a metal alcoholate of 5 to 40% by weight, preferably 15 to 25% by weight, when the sheet is 100, is used. The voice coil 1 is formed from a sheet that has been subjected to pressure and heat treatment at a temperature of 150 to 250 ° C. or calendered under these conditions.
3 is used as the bobbin 16.

With such a structure, the aromatic polyamide fibers exhibit self-fusing properties by heating under pressure, so that a filler such as mica is uniformly contained in 35 to 50 wt. % To form a flame-retardant sheet having good heat stability and excellent heat resistance, and further impregnating this sheet with a solution of metal alcoholate (here, AL (OCH ₃ ) ₃ ) at 15 to 25 wt%. And heat treatment at a temperature of 150 to 250 ° C. or calendering under these conditions improves rigidity, improves waterproofness, is lightweight, flame-retardant, rigid, heat-resistant. Bobbin 16 with excellent stability
Can be obtained. When the content of the filler is 35 wt% or less, heat resistance and rigidity are slightly lacked, and when the content is 50 wt% or more, unevenness of the sheet surface becomes large and the material properties tend to be fragile. If the metal alcoholate content is 15 wt% or less, the waterproofness and rigidity are poor, and
If the content is more than wt%, it becomes fragile.

As described above, these sheets have a good waterproof property. By cutting these sheets into strips and forming them into a tubular shape, a bobbin 16 which is lightweight and has excellent flame retardancy, rigidity and heat stability can be obtained. A coil portion 14 is formed by winding a magnet wire having good heat resistance around the outer periphery of the bobbin 16, and the outer periphery of the bobbin 16 excluding the coil portion 14 is made of kraft paper for reinforcement and insulation. The voice coil 13 for the speaker shown in FIG. 2 is obtained by winding the reinforcing paper 15.

Further, the reinforcing paper 15 made of the kraft paper is used.
By forming the voice coil 13 as a reinforcing paper using the same material as the material of the bobbin 16 according to the present invention, the above-described effect can be further enhanced.

By forming a speaker using the voice coil 13 configured as described above, even if a large input is applied and the voice coil 13 generates heat and rises in temperature, it is excellent in heat resistance, rigidity, and lightweight. Voice coil 1
3, the burnout of the bobbin 16 and the coil portion 14
A speaker capable of exhibiting stable performance without falling out of the speaker 6 can be obtained.

By adding a phenol resin fiber having excellent heat resistance and near non-combustibility to the aromatic polyamide fiber exhibiting the self-fusing property, the tear strength of the bobbin 16 can be improved and the sheet can be easily formed. The effect can be obtained. The addition amount of the phenol resin fiber is desirably 10 to 25% by weight. If it is 10 wt% or less, the above effect is small, and if it is 30 wt% or more, the physical strength is reduced.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a half sectional view showing a voice coil 18 used in the speaker according to the embodiment. The present embodiment has the same structure as that of the first embodiment except for the voice coil 18, so that the voice coil 18 is used. Descriptions other than those described above are omitted.

The voice coil 1 according to the embodiment shown in FIG.
Reference numeral 8 denotes a bobbin 16 obtained in the same manner as in Example 1 in which a layer of metal powder 17 made of a non-magnetic material is formed on the outer peripheral surface. Coil part 1 by winding a good magnet wire
4, a voice coil 18 is formed by wrapping a reinforcing paper 15 around the outer periphery of a bobbin 16 on which a layer of metal powder 17 excluding the coil portion 14 is formed for reinforcement and insulation.

The layer of the metal powder 17 is made of a non-magnetic metal such as a lightweight aluminum metal or a non-magnetic material such as an aluminum powder or an alumina powder. A layer is formed by forming a layer or by coating a resin mixed with the same metal powder 17, and either means may be used. The heat radiation is further improved, and the effect of suppressing the temperature rise is increased. As a result, the input resistance of the speaker is improved by about 10 to 15% as compared with the voice coil 13 having the configuration shown in FIG. 2 of the first embodiment. Becomes possible.

The results of comparing the heat shrinkage and the physical properties of the sheets constituting the bobbins 16 of the voice coils 13 and 18 used in the loudspeaker according to the present embodiment configured as described above with the conventional products are shown in Table 1 below. It is shown in (Table 2). Also, the results of wet heat resistance are shown in Table 3 and the results of flame retardancy are shown in Table 4.

[0027]

[Table 1]

As is clear from Table 1, the sheet according to the present embodiment has excellent heat resistance, good dimensional stability, and is sufficiently satisfactory as a voice coil of a large input speaker.

[0029]

[Table 2]

As is clear from Table 2, the sheet according to the present example is lightweight, excellent in rigidity and shows good results.

[0031]

[Table 3]

As shown in Table 3, the sheet according to the present embodiment exhibits excellent water resistance.

[0033]

[Table 4]

Table 4 shows the flame retardancy.
It is believed that there is no risk of ignition of the voice coil composed of the sheet according to the present embodiment.

[0035]

As described above, the speaker according to the present invention has the following features.
A sheet made of aromatic polyamide fiber and inorganic filler impregnated with a metal alcoholate solution that has excellent heat resistance and exhibits self-fusing properties by heating under pressure and calendering. By using a voice coil that uses a bobbin as the seat that has been made, it can withstand large input application sufficiently, and because it uses a voice coil that realizes flame retardancy, there is little danger of ignition and combustion, etc. It is of great practical value that can exert its effect sufficiently as a door speaker for vehicles.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a configuration of a speaker according to a first embodiment of the present invention.

FIG. 2 is a half sectional front view showing the voice coil according to the embodiment;

FIG. 3 is a half sectional front view showing a voice coil according to the second embodiment;

FIG. 4 is a half sectional view showing a configuration of a conventional speaker.

FIG. 5 is a half sectional front view showing a conventional voice coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic circuit 2 Center pole part 3 Lower plate 4 Magnet 5 Upper plate 6 Frame 7 Gasket 8 Diaphragm 10 Damper 11 Magnetic gap 12 Dust cap 13 Voice coil 14 Coil part 15 Reinforcement paper 16 Bobbin 17 Metal powder 18 Voice coil

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04R 9/04 104 C08K 3/00 C08L 77/10

Claims (3)

(57) [Claims] 1. An aromatic polyamide fiber having excellent heat resistance and exhibiting self-fusing property by heating under pressure or calendering, and containing an inorganic filler as a main component.
A coil is wound around a bobbin formed from a sheet obtained by coating or impregnating a metal sheet in a ratio of 5 to 40% by weight with a papermaking sheet mixed with 抄 50% by weight, and heating or calendering the sheet. A voice coil, a magnetic circuit forming a magnetic gap into which the voice coil fits, a frame coupled to an upper surface of the magnetic circuit, and an outer peripheral portion coupled to a peripheral edge of the frame, and the voice coil coupled to a central portion. Speaker made of a vibrating plate. 2. The speaker according to claim 1, wherein the bobbin material constituting the voice coil contains 5 to 30% by weight of phenol resin fibers. 3. The bobbin material constituting the voice coil is formed by depositing a metal made of a non-magnetic material on the surface and then coating the resin, or coating the surface with a resin mixed with a metal powder made of the non-magnetic material. The speaker according to claim 1, wherein